Design of Yagi-Uda Antenna With Multiple Driven Elements

Abstract

In this paper, we present a novel design for an end-fire antenna, which generalizes the concept of conventional Yagi-Uda antenna by introducing multiple driven elements. Through using the method of maximum power transmission efficiency, the optimal distribution of excitations for the multiple driven elements can be obtained, and the end-fire gain of the array can be significantly improved in comparison with the conventional Yagi-Uda antenna with a single driven element. In order to demonstrate the new idea, two different types of antenna arrays are designed and fabricated. The first design uses a split-ring resonator (SRR) as radiating element. Compared to similar planar Yagi-Uda SRR antenna arrays previously reported, the number of antenna elements can be reduced from fifteen to eight, and the longitudinal dimension is significantly reduced by 46% while the same performances are maintained with the gain reaching 11.7 dBi at 5.5 GHz. In the second design, printed half-wavelength dipoles are used as the antenna elements. It is shown that an eight-element dipole array with four driven elements has a peak gain of 13.4 dBi at 2.45 GHz, which is 1.8 dB higher than the conventional printed Yagi-Uda dipole antenna array with the same number of elements.

Influence analysis of director’s elements on the circular Yagi disc antenna performance at 1.8 GHz

“…The spacing of the reflector from the driven element is about 0.1λ to 0.25λ. The spacing also depends on bandwidth, gain, F/B ratio and sidelobe pattern specifications [22], [23]. The Yagi Disc antenna is fed by an RG58 50 Ω coaxial cable.…”

The Method of Maximum Power Transmission Efficiency for the Design of Antenna Arrays

“…Typically the MMPTE can be applied to the design of focused antenna arrays, smart (beam steering) antenna arrays, end-fire antenna arrays, multi-beam antenna arrays, and the shaped beam antenna arrays. By introducing a single test Rx antenna in the direction where the radiation intensity needs to be maximized or minimized, the UMMPTE (where only one positive eigenvalue is involved) can be used to design the focused antennas [11]- [17], smart antennas [18]- [21], end-fire antennas [24] [25], and polarization-reconfigurable antennas. By introducing a test Rx array, the CMMPTE and WMMPTE (where multiple positive eigenvalues are involved) can be used to shape beam patterns [22][23], and design antenna arrays with multiple focal points [17], and multiple beam antennas [26][27].…”

“…The ODE for the array can be obtained from MMPTE, and a feeding network can then be built from the ODE to achieve the end-fire function. A novel design for end-fire antenna is proposed in [24], in which the conventional Yagi-Uda antenna is generalized by introducing multiple driven elements. The ODE for the driven elements is obtained from UMMPTE, and the end-fire gain of the array is considerably improved, while the number of elements and the longitudinal dimension of the array are substantially reduced in comparison with the conventional Yagi-Uda antenna with a single driven element.…”

“…The ODE for the driven elements is obtained from UMMPTE, and the end-fire gain of the array is considerably improved, while the number of elements and the longitudinal dimension of the array are substantially reduced in comparison with the conventional Yagi-Uda antenna with a single driven element. Two different arrays are designed in [24]. The first design operates at 5.5GHz and uses split-ring resonator (SRR) as radiating element.…”